Particles, connecting material and connection structure

ABSTRACT

Particles that can suppress the occurrence of cracking or peeling during a thermal cycle in a connection part that connects two members to be connected, further can suppress the variation in thickness in the connection part, and can increase the connection strength are provided. The particles according to the present invention are particles used to obtain a connecting material for forming a connection part that connects two members to be connected, and the particles are used for forming the connection part such that thickness of the connection part after connection is twice or less the average particle diameter of the particles before connection, or the particles have an average particle diameter of 1 μm or more and 300 μm or less, the particles have a 10% K value of 30 N/mm 2  or more and 3000 N/mm 2  or less, and the particles have a particle diameter CV value of 10% or less.

TECHNICAL FIELD

The present invention relates to particles used to obtain a connectingmaterial for forming a connection part that connects two members to beconnected. Further, the present invention relates to a connectingmaterial and a connection structure, provided with the above particles.

BACKGROUND ART

In a non-insulation type semiconductor device that is one of the powersemiconductor devices used for an inverter or the like, a member forfixing a semiconductor element is also one of the electrodes of thesemiconductor device. For example, in a semiconductor device in which apower transistor is mounted on a fixing member using a Sn-Pb-basedsoldering material, the fixing member (base material) connecting twomembers to be connected serves as a collector electrode of the powertransistor.

In addition, it is known that when the particle diameter of a metalparticle becomes small to a size of 100 nm or less and the number ofconstituent atoms is reduced, the surface area ratio to the volume ofthe particle rapidly increases, and the melting point or the sinteringtemperature decreases largely as compared with that in the bulk state. Amethod in which by utilizing the low temperature firing function, and byusing the metal particles having an average particle diameter of 100 nmor less, the surfaces of which are coated with an organic substance, asa connecting material, the connection is performed by decomposing theorganic substance by heating, and by sintering the metal particles toone another is known. In this connection method, metal particles afterconnection change to a bulk metal, and at the same time, connection bymetal bonding is obtained in the connection interface, therefore, theheat resistance, the connection reliability, and the heat dissipationbecome extremely high. A connection material for performing such aconnection has been disclosed, for example, in the following PatentDocument 1.

In Patent Document 1, a connecting material containing one or more kindsof the metal particle precursors selected from particles of a metaloxide, a metal carbonate, or a metal carboxylate, and a reducing agentthat is an organic substance has been disclosed. The average particlediameter of the metal particle precursors is 1 nm or more and 50 μm orless. In the total parts by mass in the above connection material, thecontent of the metal particle precursors exceeds 50 parts by mass and 99parts by mass or less.

In the following Patent Document 2, a composite material containing athermally conductive metal having a melting point (a), and siliconeparticles (b) has been disclosed. The silicone particles (b) aredispersed in the thermally conductive metal (a).

RELATED ART DOCUMENT Patent Document

Patent Document 1: JP 2008-178911 A

Patent Document 2: JP 2013-243404 A

SUMMARY OF THE INVENTION Problems to be Solved by the Invention

In the above collector electrode, a current of several amperes or moreflows during operation of the semiconductor device, and the transistorchip generates heat. As described above, the connection part thatconnects two members to be connected is exposed to thermal cyclingconditions. A member to be connected such as a semiconductor wafer and asemiconductor chip is easily warped by a thermal cycle, as a result,cracks tend to occur in the member to be connected or the connectionpart, and peeling of the member to be connected is easy to occur. Withthe conventional connecting material, it is difficult to sufficientlysuppress the occurrence of cracking and peeling.

In addition, it is preferred that the distance between the two membersto be connected that are connected by the connection part is uniform.Therefore, it is preferred that the variation in the thickness of theconnection part is small. With the conventional connecting material, itis difficult to control the distance between the two members to beconnected with high accuracy. In Patent Document 2, silicone particlesare not used as gap control particles.

An object of the present invention is to provide particles capable ofsuppressing the occurrence of cracking or peeling during a thermal cyclein a connection part that connects two members to be connected, andfurther capable of suppressing the variation in thickness in theconnection part and increasing the connection strength. Further, anobject of the present invention is also to provide a connecting materialand a connection structure, provided with the above particles.

Means for Solving the Problems

According to a broad aspect of the present invention, particles that areused to obtain a connecting material for forming a connection part thatconnects two members to be connected, in which the particles are usedfor forming the connection part such that thickness of the connectionpart after connection is twice or less the average particle diameter ofthe particles before connection, or the particles have an averageparticle diameter of 1 μm or more and 300 μm or less, the particles havea 10% K value of 30 N/mm² or more and 3000 N/mm² or less, and theparticles have a particle diameter CV value of 10% or less, areprovided.

In a certain specific aspect of the particles according to the presentinvention, the particles are used for forming a connection part suchthat, thickness of the connection part after connection is twice cr lessthe average particle diameter of the particles before connection.

In a certain specific aspect of the particles according to the presentinvention, the particles have an average particle diameter of 1 μm ormore and 300 μm or less.

In a certain specific aspect of the particles according to the presentinvention, the number of aggregated particles per million particles ofthe above particles is 100 or less.

In a certain specific aspect of the particles according to the presentinvention, the particles have a thermal decomposition temperature of200° C. or more.

In a certain specific aspect of the particles according to the presentinvention, a material for the particles contains a vinyl compound, a(meth)acrylic compound, an α-olefin compound, a diene compound, or asilicone compound.

In a certain specific aspect of the particles according to the presentinvention, the particles each have no conductive part on an outersurface part thereof.

In a certain specific aspect of the particles according to the presentinvention, the particles each have a base material particle, and aconductive part disposed on a surface of the base material particle.

In a certain specific aspect of the particles according to the presentinvention, a material for the conductive part contains nickel, gold,silver, copper, or tin.

In a certain specific aspect of the particles according to the presentinvention, the particles are used for forming the connection part suchthat one particle is in contact with both of the two members to beconnected.

According to a broad aspect of the present invention, a connectingmaterial being used for forming a connection part that connects twomembers to be connected, and containing the above-described particles,and a resin or metal atom-containing particles is provided.

In a certain specific aspect of the connecting material according to thepresent invention, the connecting material contains the metalatom-containing particles, and a thermal decomposition temperature ofthe particles is higher than a melting point of the metalatom-containing particles.

In a certain specific aspect of the connecting material according to thepresent invention, the connecting material contains the metalatom-containing particles, and the connecting material is used forforming the connection part by melting the metal atom-containingparticles followed by solidifying the metal atom-containing particles.

According to a broad aspect of the present invention, a connectionstructure in which a first member to be connected, a second member to beconnected, and a connection part that connects the first member to beconnected and the second member to be connected are included, and amaterial for the connection part is the above-described connectingmaterial is provided.

Effect of the Invention

The particles according to the present invention are particles used toobtain a connecting material for forming a connection part that connectstwo members to be connected. In the particles according to the presentinvention, the particles are used for forming the connection part suchthat thickness of the connection part after connection is twice or lessthe average particle diameter of the particles before connection, or theparticles have an average particle diameter of 1 μm or more and 300 μmor less, the particles have a 10% K value of 30 N/mm² or more and 3000N/mm² or less, and the particles have a particle diameter CV value of10% or less, therefore, when a connection part that connects two membersto be connected is formed by a connecting material containing the aboveparticles, the occurrence of cracking or peeling during a thermal cyclecan be suppressed, further the variation in thickness in the connectionpart can be suppressed, and the connection strength can be increased.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a sectional view showing the particle according to the firstembodiment of the present invention.

FIG. 2 is a sectional view showing the particle according to the secondembodiment of the present invention.

FIG. 3 is a sectional view showing the particle according to the thirdembodiment of the present invention.

FIG. 4 is a front sectional view schematically showing a connectionstructure using the particle according to the second embodiment of thepresent invention.

MODES FOR CARRYING OUT THE INVENTION

Hereinafter, details of the present invention will be described.

(Particles)

The particles according to the present invention are particles used toobtain a connecting material for forming a connection part that connectstwo members to be connected.

The particles according to the present invention are (1) used forforming the connection part such that thickness of the connection partafter connection is twice or less the average particle diameter of theparticles before connection, or (2) the particles having an averageparticle diameter of 1 μm or more and 300 μm or less. The presentinvention may have the constitution of the above (1), may have theconstitution of the above (2), or may have both of the constitutions ofthe above (1) and (2).

The particles according to the present invention have a 10% K value of30 N/mm² or more and 3000 N/mm² or less. The particles according to thepresent invention have a particle diameter CV value of 10% or less.

In the present invention, the above constitution is provided, therefore,in a connection part that connects two members to be connected, theoccurrence of cracking or peeling of the members to toe connected duringa thermal cycle can be suppressed, further the variation in thickness inthe connection part can foe suppressed, and the connection strength canbe increased.

In the present invention, in the connection part, the particles can actas a gap control material (gap control particles), and in particular,can act as a gap control material (gap control particles) during athermal cycle.

It is preferred that the particles according to the present inventionare (1) used for forming the connection part such that thickness of theconnection part after connection is twice or less the average particlediameter of the particles before connection.

The 10% K value is a compression modulus when a particle is compressedby 10%. From the viewpoint of exhibiting the gap control characteristicsand of suppressing the occurrence of cracking or peeling during athermal cycle, the 10% K value of the particles is 30 N/mm² or more and3000 N/mm² or less. From the viewpoint of exhibiting the gap controlcharacteristics and of further suppressing the occurrence of cracking orpeeling during a thermal cycle, the 10% K value is preferably 80 N/mm²or more, and more preferably 300 N/mm² or more. From the viewpoint ofexhibiting the gap control characteristics and of further suppressingthe occurrence of cracking or peeling during a thermal cycle, the 10% Kvalue of the particles is preferably 2500 N/mm² or less, more preferably1500 N/mm² or less, and furthermore preferably less than 980 N/mm².

The 10% K value of the particles can be measured as follows.

Using a micro compression testing machine, a particle is compressed at asmooth indenter end face of a cylinder (diameter of 50 μm, made ofdiamond) under the condition of loading a maximum test load of 20 mNover 60 seconds at 25° C. The load value (N) and compressiondisplacement (mm) at this time are measured. From the obtainedmeasurement values, the 10% K value (compression modulus) can bedetermined by the following equation. As the micro compression testingmachine, for example, “Fischer Scope H-100” manufactured by FISCHERINSTRUMENTS K.K., or the like is used.

10% K value (N/mm²)=(3/2^(1/2))·F·S^(−3/2)·R^(−1/2)

F: Load value (N) when the particle is compressed and deformed by 10%

S: Compression displacement (mm) when the particle is compressed anddeformed by 10%

R: Radius of the particle (mm)

The coefficient of variation (CV value) of the particle diameter of theparticles is 10% or less. From the viewpoint of further suppressing theoccurrence of cracking or peeling during a thermal cycle, the particlediameter CV value of the particles is preferably 7% or less, and morepreferably 5% or less. The lower limit of the particle diameter CV valueof the particles is not particularly limited. The CV value may also be0% or more.

The coefficient of variation (CV value) is represented by the followingequation.

CV value(%)=(ρ/Dn)×100

ρ: Standard deviation of the particle diameter of the particle

Dn: Average value of the particle diameter of the particle

It is preferred that the average particle diameter of the particles is 1μm or more and 300 μm or less. However, when the constitution of theabove (1) is provided, the average particle diameter of the particlesmay also be less than 1 μm, or may exceed 300 μm. The average particlediameter of the particles may also exceed 15 μm, may also exceed 20 μm,or may also exceed 50 μm.

From the viewpoint of exhibiting the gap control characteristics and offurther suppressing the occurrence of cracking or peeling during athermal cycle, the average particle diameter of the particles ispreferably 1 μm or more, and is preferably 300 μm or less. From theviewpoint of exhibiting the gap control characteristics and of furthersuppressing the occurrence of cracking or peeling during a thermalcycle, the average particle diameter of the particles is preferably 5 μmor more, more preferably 10 μm or more, and furthermore preferably 20 μmor more. From the viewpoint of exhibiting the gap controlcharacteristics and of further suppressing the occurrence of cracking orpeeling during a thermal cycle, the average particle diameter of theparticles is preferably 200 μm or less, more preferably 150 μm or less,and furthermore preferably 100 μm or less.

The average particle diameter of the particles can be determined byobserving the particles with a scanning electron microscope, and byarithmetically averaging the maximum diameters of 50 particlesarbitrarily selected in the observed image.

In the present invention, it is preferred that the particles be used forforming the connection part such that one particle is in contact withboth of the two members to be connected. In this case, one particle isin contact with one member to be connected on one side of the particle,and is in contact with another member to be connected on the other sideof the particle.

Hereinafter, the present invention will be specifically described whilemaking reference to drawings. In the following embodiments of particles,some portions different from each other can be replaced.

FIG. 1 is a sectional view showing the particle according to the firstembodiment of the present invention.

A particle 1 shown in FIG. 1 is a particle having no conductive part.The particle 1 is, for example, a particle excluding metal particles.The particle 1 is, for example, a resin particle.

As the particle 1, the particles according to the present invention eachmay not have a conductive part. When the particle has no conductivepart, the particle can be used without forming any conductive part on asurface of the particle. As a particle described later, the particlesaccording to the present invention each may have a base materialparticle and a conductive part disposed on a surface of the basematerial particle.

FIG. 2 is a sectional view showing the particle according to the secondembodiment of the present invention.

A particle 11 shown in FIG. 2 is a particle having a conductive part.The particle 11 has a base material particle 12, and a conductive part13. The conductive part 13 is disposed on a surface of the base materialparticle 12. The conductive part 13 is in contact with a surface of thebase material particle 12. The particle 11 is a coated particle in whicha surface of the base material particle 12 is coated with the conductivepart 13. In the particle 11, the conductive part 13 is a single-layeredconductive part (conductive layer).

FIG. 3 is a sectional view showing the particle according to the thirdembodiment of the present invention.

A particle 21 shown in FIG. 3 is a conductive particle having aconductive part. The particle 21 has a base material particle 12, and aconductive part 22. The conductive part 22 as a whole has a firstconductive part 22A on the base material particle 12 side, and a secondconductive part 22B on the opposite side of the base material particle12 side.

As compared the particle 11 with the particle 21, only the conductivepart is different from each other. That is, in the particle 11, theconductive part 13 having a single-layer structure is formed, but in theparticle 21, a two-layer structure of a first conductive part 22A and asecond conductive part 22B is formed. The first conductive part 22A andthe second conductive part 22B are formed as separate conductive parts.In the particle 21, the conductive part 22 is a multi-layered conductivepart (conductive layer).

The first conductive part 22A is disposed on a surface of the basematerial particle 12. The first conductive part 22A is disposed betweenthe base material particle 12 and the second conductive part 22B. Thefirst conductive part 22A is in contact with the base material particle12. Therefore, the first conductive part 22A is disposed on a surface ofthe base material particle 12, and the second conductive part 22B isdisposed on a surface of the first conductive part 22A.

The particles 1, 11, and 21 each have no protrusions on the outersurface thereof. The particles 1, 11, and 21 each are spherical.

As the particles 1, 11, and 21, the particles according to the presentinvention each may also have no protrusions on the outer surfacethereof, may also have no protrusions on the outer surface of theconductive part, or may also be spherical.

It is preferred that in the particles, the number of aggregatedparticles per million particles of the above particles is 100 or less.The aggregated particles are particles in which one particle is incontact with at least one other particle. For example, when threeaggregates in each of which three particles are aggregated (aggregate ofthree particles) are included per million particles of the aboveparticles, the number of aggregated particles per million particles ofthe above particles is 9. As the measurement method of the number of theaggregated particles, a method in which the aggregated particles arecounted using a microscope set at a magnification at which around 50,000particles are observed in one field of view, and the number ofaggregated particles is measured as the total of 20 fields of view, orthe like can be mentioned.

As the method for setting the number of aggregated particles to be 100or less per million particles of the above particles, for example, amethod in which the above particles each are made into a form of aconductive particle having the above-described conductive part, a methodin which particles each are made into a form of a particle on a surfaceof which continuous or discontinuous coated part (coated layer) isprovided for suppressing the aggregation, a method for modifying asurface of a particle with a crosslinkable compound, or the like can bementioned.

As the method for forming the continuous coated part described above,for example, a method in which a particle is coated with a resin havinga hardness higher than that of the particle before the coated part isformed thereon can be mentioned. As the resin that is a material for thecoated part, a resin similar to the material for the particles A andbase material particles described later, a hydrophilic resin, or thelike can be mentioned. The resin that is a material for the coated partis preferably a divinylbenzene-styrene copolymer, polyvinyl alcohol,polyvinyl pyrrolidone, or polyacrylic acid.

As the method for forming the discontinuous coated part described above,for example, a method in which fine particles are deposited on a surfaceof the particle before the coated part is formed thereon to coat theparticle can be mentioned. As the fine particles that are a material forthe coated part, inorganic fine particles of silica, titania, alumina,zirconia, magnesium oxide, zinc oxide, or the like; resin fineparticles; and organic-inorganic hybrid fine particles; or the like canbe mentioned.

As the method for modifying a surface of a particle with a crosslinkablecompound, for example, a method in which a polyfunctional silanecoupling agent or a polyfunctional carboxylic acid is reacted with themultiple hydroxyl groups that are present on a surface of a particle, orthe like can be mentioned.

Since it is preferred that the particles be not thermally decomposed inthe connection part, it is preferred that the particles have a thermaldecomposition temperature of 200° C. or more. The thermal decompositiontemperature of the particles is preferably 220° C. or more, morepreferably 250° C. or more, and furthermore preferably 300° C. or more.Note that when the particle has a base material particle and aconductive part, a temperature at which first thermal decomposition isgenerated in either one of the base material particle and the conductivepart is defined as the thermal decomposition temperature of theparticle.

Hereinafter, other details of particles will be described. Note that inthe following description, the expression “(meth)acrylic” means one orboth of “acrylic”and “methacrylic”, the expression “(meth)acrylate”means one or both of “acrylate” and “methacrylate”, and the expression“(meth)acryloyl” means one or both of “acryloyl”and “methacryloyl”. Theexpression “(un)saturated” means either saturated or unsaturated.

[Particle having no Conductive Part and Base Material Particle]

In the particle according to the present invention, a particle having noconductive part is referred to as a particle A. The particle accordingto the present invention may have a base material particle and aconductive part disposed on a surface of the base material particle.

The 10% K value of the particle can also be adjusted by thecharacteristics of the particle A and the base material particle. Theparticle A and the base material particle may not have pores, may havepores, may have a single pore, or may be porous.

As the particle A and the base material particle, a resin particle, aninorganic particle excluding a metal particle, an organic-inorganichybrid particle, or the like can be mentioned. The particle A and thebase material particle may be a core-shell particle provided with a coreand a shell disposed on a surface of the core. The core may be anorganic core. The shell may be an inorganic shell. Each of the particleA and the base material particle are preferably a particle excluding ametal particle, and more preferably a resin particle, an inorganicparticle excluding a metal particle, or an organic-inorganic hybridparticle. A resin particle or an organic-inorganic hybrid particle isparticularly preferred because of being more excellent effect of thepresent invention.

From the viewpoint of further suppressing the occurrence of cracking orpeeling during a thermal cycle, it is preferred that the particle A andthe base material particle each are a resin particle. Examples of theresin include, for example, polyolefin, polyene, poly(meth)acrylic acidester, and polysiloxane.

Examples of the material for the particle A and the base materialparticle include, for example, a vinyl compound, a (meth)acryliccompound, an α-olefin compound, a diene compound, a silicone compound,and an epoxy compound. From the viewpoint of further suppressing theoccurrence of cracking or peeling during a thermal cycle, the materialfor the particle A and the base material particle is preferably a vinylcompound, a (meth)acrylic compound, an α-olefin compound, a dienecompound, or a silicone compound, and more preferably a vinyl compound,a (meth)acrylic compound, a diene compound, or a silicone compound. Whenthe particle has no conductive part, the material for the particle ispreferably a vinyl compound, a (meth)acrylic compound, an α-olefincompound, a diene compound, or a silicone compound, and more preferablya vinyl compound, a (meth)acrylic compound, a diene compound, or asilicone compound. When the particle has a base material particle and aconductive part, the material for the base material particle ispreferably a vinyl compound, a (meth)acrylic compound, an α-olefincompound, a diene compound, or a silicone compound, and more preferablya vinyl compound, a (meth)acrylic compound, a diene compound, or asilicone compound.

With the use of the above material, as the method for obtaining theabove particle A and base material particle, for example, a method ofradical polymerization, ionic polymerization, coordinationpolymerization, ring-opening polymerization, isomerizationpolymerization, cyclic polymerization, elimination polymerization,polyaddition, polycondensation, or addition condensation, or the likecan be mentioned.

When the particle A and the base material particle are obtained bypolymerizing a polymerizable monomer having an ethylenically unsaturatedgroup, from the viewpoint of increasing the heat resistance, a compoundhaving a fluorene skeleton (hereinafter, referred to as a “fluorenecompound”) can be used as the polymerizable monomer having anethylenically unsaturated group. The fluorene skeleton may be present ata position other than the terminal, may be present at the terminal, ormay be present in the side chain.

As the fluorene compound, a compound having a bisaryl fluorene skeleton,or the like can be mentioned.

The compound having a bisaryl fluorene skeleton is a compound in whichtwo aryl groups are bonded to a 5-membered ring of a fluorene skeleton.Further, the aryl group may have a (meth)acryloyl group or a vinylgroup. For example, as the group bonded to a benzene ring, the arylgroup may have —O(C₂H₄O)_(m)COCH═CH₂ group (m is an integer of 1 to 13),—O(C₂H₄O)_(m)COCH═CHCH₃ group (m is an integer of 1 to 13),—O—C₂H₄O—COCH═CH₂ group, —O—C₂H₄O—COCH═CHCH₃ group, —O—CH₂—CH═CH₂ group,or the like. The groups described above may be bonded to a p-position tothe bonding site of the fluorene skeleton of the benzene ring in thearyl group.

As a specific example of the fluorene compound, a compound representedby the following formula (1), or the like can be mentioned.

In the above formula (1), R1 and R2 each represent a hydrogen atom,—O(C₂H₄O)_(m)COCH═CH₂ group (m is an integer of 1 to 13),—O(C₂H₄O)_(m)COCH═CHCH₃ group (m is an integer of 1 to 13),—O—C₂H₄O—COCH═CH₂ group, —O—C₂H₄O—COCH═CHCH₃ group, or —O—CH₂—CH═CH₂group.

As a commercially available product of the fluorene compound, “OGSOLEA-0300” manufactured by Osaka Gas Chemicals Co., Ltd., and“9,9′-bis(4-allyloxyphenyl) fluorene” manufactured by TOKYO CHEMICALINDUSTRY CO., LTD., or the like can be mentioned.

When the material for the particle A and base material particle isobtained by metathesis polymerization, a polymer of a metathesispolymerizable monomer, and a metathesis polymerizable compound such as ametathesis polymerizable oligomer are suitably used. For example, bysubjecting the metathesis polymerizable compound to ring-openingpolymerization in the presence of a catalyst, a metathesispolymerization compound is obtained.

The metathesis polymerizable compound has metathesis polymerizationactivity. The metathesis polymerizable compound is not particularlylimited, and is preferably a cyclic unsaturated compound from theviewpoint of the polymerization reaction activity. The metathesispolymerizable compound may also be a functional group-containingcompound. Examples of the functional group-containing compound include,for example, a compound with a functional group such as a hydroxylgroup, a carboxyl group, an amino group, an ester group, an acetoxygroup, an alkoxy group, a halogen group, a carbonyl group, a mercaptogroup, an epoxy group, a silyl group, an oxazoline group, a sulfonicacid group, a maleimide group, an azlactone group, and a vinyl group.The functional group in the functional group-containing compound mayalso be a polar functional group, or may also be a non-polar functionalgroup.

As the cyclic unsaturated compound, a monocyclic olefin such ascyclobutene, cyclopentene, cyclohexene, cyclooctene, or cyclooctadiene,or a derivative thereof; a polycyclic olefin such as 2-norbornene,2,5-norbornadiene, 5-methyl-2-norbornene, 5-ethylidene-2-norbornene,5-phenylnorbornene, dicyclopentadiene, dihydrodicyclopentadien,tetracyclodcdecene, tricyclopentadiene, or tetracyclopentadiene, or aderivative thereof; a hetero atom-containing cycloolefin such as2,3-dihydrofuran, exo-3,6-epoxy-1,2,3,6-tetrahydrophthalic anhydride,9-oxabicyclo[6.1.0]non-4-ene,exo-N-methyl-7-oxabicyclo[2.2.1]hept-5-ene-2,3-dicarboximide, or1,4-dihydro-1,4-epoxynaphthalene; or the like is suitably used. Thecyclic unsaturated compounds described above may be used singly, or twoor more kinds thereof in combination.

From the viewpoint of the reactivity and the cost, the metathesispolymerizable compound is preferably cyclooctadiene, 2-norbornene, ordicyclopentadiene, or a derivative thereof.

It is preferred that the catalyst used for polymerization of themetathesis polymerizable compound is an organic metal complex catalyst.Examples of the catalyst used for polymerization of the metathesispolymerizable compound include a chloride having any one of the metalsselected from Ti, V, Cr, Zr, Nb, Mo, Ru, Hf, Ta, W, Re, Os, or Ir as thecentral metal; an alkylene complex; a vinylidene complex; a carbenecomplex such as allenylidene; and a metathesis reactive complex such asa carbyne complex. A catalyst in which the central metal is ruthenium(Ru) is preferred.

Further, the metathesis polymerizable compound can be polymerized by aknown polymerization method.

When the metathesis polymerization compound is used, as the method foreasily adjusting the 10% K value to a desired value, a method in whichhydrogenation reaction is performed after ring-opening polymerization atthe time of synthesis can be mentioned. Note that the method ofhydrogenation reaction is a known method. For example, by using aWilkinson complex, cobalt acetate/triethylaluminum, nickelacetylacetate/triisobutylaluminum, palladium-carbon, a rutheniumcomplex, ruthenium-carbon, nickel-kieselguhr or the like, thehydrogenation reaction can be performed.

Examples of the material for the particle A and the base materialparticle include a condensate obtained from one or more kinds of thecompounds of an (un)saturated hydrocarbon, an aromatic hydrocarbon, an(un)saturated fatty acid, an aromatic carboxylic acid, an (un)saturatedketone, an aromatic ketone, an (un)saturated alcohol, an aromaticalcohol, an (un)saturated amine, an aromatic amine, an (un)saturatedthiol, an aromatic thiol, and an organic silicon compound, and a polymerobtained from one or more kinds of those compounds.

Examples of the condensate and the polymer include, for example, apolyolefin resin of polyethylene, polypropylene, polystyrene, polyvinylchloride, polyvinylidene chloride, polyisobutylene, polybutadiene, orthe like; an acrylic resin of polymethyl methacrylate, polymethylacrylate, or the like; polyalkylene terephthalate, polycarbonate,polyamide, a phenol formaldehyde resin, a melamine formaldehyde resin, abenzoguanamine formaldehyde resin, a urea formaldehyde resin, a phenolresin, a melaraine resin, a benzoguanamine resin, a urea resin, an epoxyresin, an unsaturated polyester resin, a saturated polyester resin,polysulfone, polyphenylene oxide, polyacetal, polyimide, polyamideimide,polyether ether ketone, polyethersulfone, and a polymer obtained bypolymerizing various polymerizable monomers having an ethylenicallyunsaturated group singly or two or more kinds thereof in combination.Since the hardness of the particle A and the base material particle canbe easily controlled within a suitable range, the resin for forming theresin particle is preferably a polymer obtained by polymerizingpolymerizable monomers having multiple ethylenically unsaturated groupssingly or two or more kinds thereof in combination.

When the particle A and the base material particle are obtained bypolymerization such as radical polymerization, ionic polymerization orcoordination polymerization, a polymerizable monomer having anethylenically unsaturated group is suitably used. As long as thepolymerizable monomer having an ethylenically unsaturated group has anethylenically unsaturated group, the molecular weight, the number ofethylenically unsaturated groups, and the like are not particularlylimited. Examples of the polymerizable monomer having an ethylenicallyunsaturated group include a non-crosslinkable monomer, and acrosslinkable monomer.

Examples of the non-crosslinkable monomer include, for example, as thevinyl compound, a styrene-based monomer such as styrene, α-methylstyrene, and chlorostyrene; a vinyl ether compound such as methyl vinylether, ethyl vinyl ether, and propyl vinyl ether; an acid vinyl estercompound such as vinyl acetate, vinyl butylate, vinyl laurate, and vinylstearate; and a halogen-containing monomer such as vinyl chloride, andvinyl fluoride: as the (meth)acrylic compound, an alkyl (meth)acrylatecompound such as methyl (meth)acrylate, ethyl (meth)acrylate, propyl(meth)acrylate, butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate,lauryl (meth)acrylate, cetyl (meth)acrylate, stearyl (meth)acrylate,cyclohexyl (meth)acrylate, and isobornyl (meth)acrylate; an oxygenatom-containing (meth)acrylate compound such as 2-hydroxyethyl(meth)acrylate, glycerol (meth)acrylate, polyoxyethylene (meth)acrylate,and glycidyl (meth)acrylate; a nitrile-containing monomer such as(meth)acrylonitrile; and a halogen-containing (meth)acrylate compoundsuch as trifluoromethyl (meth)acrylate, and pentafluoroethyl(meth)acrylate: as the α-olefin compound, an olefin compound such asdiisobutylene, isobutylene, LINEALENE, ethylene, and propylene: and asthe conjugated diene compound, isoprene, butadiene, and the like.

Examples of the crosslinkable monomer include, for example, as the vinylcompound, a vinyl-based monomer such as divinylbenzene,1,4-divinyloxybutane, divinyl sulfone, and 9,9′-bis(4-allyloxyphenyl)fluorene: as the (meth)acrylic compound, a polyfunctional (meth)acrylatecompound such as tetramethylolmethane tetra(meth)acrylate,tetramethylolmethane tri(meth)acrylate, tetramethylolmethanedi(meth)acrylate, trimethylolpropane tri(meth)acrylate,dipentaerythritol hexa(meth)acrylate, dipentaerythritolpenta(meth)acrylate, glycerol tri(meth)acrylate, glyceroldi(meth)acrylate, (poly)ethylene glycol di(meth)acrylate,(poly)propylene glycol di(meth)acrylate, (poly)tetramethylene glycoldi(meth)acrylate, and 1,4-butanediol di(meth)acrylate: as the allylcompound, triallyl (iso)cyanurate, triallyl trimellitate, diallylphthalate, diallyl acrylamide, and diallyl ether: and as the siliconecompound, a silane alkoxide compound such as tetramethoxysilane,tetraethoxysilane, methyltrimethoxysilane, methyltriethoxysilane,ethyltrimethoxysilane, ethyltriethoxysilane, isopropyl trimethoxysilane,isobutyltrimethoxysilane, cyclohexyl trimethoxysilane,n-hexyitrimethoxysilane, n-octyltriethoxysilane,n-decyltrimethoxysilane, phenyltrimethoxysilane,dimethyldimethoxysilane, dimethyldiethoxysilane,diisopropyldimethoxysilane, trimethoxysilyl styrene,γ-(meth)acryloxypropyltrimethoxysilane,1,3-divinyltetramethyldisiloxane, methylphenyldimethoxysilane, anddiphenyldimethoxysilane; a polymerizable double bond-containing silanealkoxide such as vinyltrimethoxysilane, vinyltriethoxysilane,dimethoxymethylvinylsilane, dimethoxyethylvinylsilane,diethoxymethylvinylsilane, diethoxyethylvinylsilane,ethylmethyldivinylsilane, methylvinyldimethoxysilane,ethylvinyldiethoxysilane, methylvinyldiethoxysilane,ethylvinyldiethoxysilane, p-styryltrimethoxysilane,3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxy silane, 3-methacryloxypropylmethyldiethoxysilane,3-methacryloxypropyl triethoxy silane, and3-acryloxypropyltrimethoxysilane; a cyclic siloxane such asdecamethylcyclopentasiloxane; a modified (reactive) silicone oil such asone-terminal silicone oil, both-terminal silicone oil, and side-chaintype silicone oil; and a carboxyl group-containing monomer such as(meth)acrylic acid, maleic acid, and maleic anhydride.

By polymerizing the polymerizable monomer having an ethylenicallyunsaturated group by a known method, the resin particle can be obtained.As this method, for example, a method in which suspension polymerizationis performed in the presence of a radical polymerization initiator, amethod in which non-crosslinked seed particles are swollen with monomersand a radical polymerization initiator and the monomers are polymerized,or the like can be mentioned.

As the material for the particle A and the base material particle,polysiloxane is suitably used. The polysiloxane is a polymerizationproduct of a silane compound and is obtained by polymerization of asilane compound.

Examples of the silane compound include a silane alkoxide compound suchas tetramethoxysilane, tetraethoxysilane, methyltrimethoxysilane,methyltriethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane,isopropyitrimethoxysilane, isobutyltrimethoxysilane, cyclohexyltrimethoxysilane, n-hexyltrimethoxysilane, n-octyltriethoxysilane,n-decyltrimethoxysilane, phenyltrimethoxysilane,dimethyldimethoxysilane, dimethyidlethoxysilane,diisopropyldimethoxysilane, trimethoxysilyl styrene,γ-(meth)acryloxypropyltrimethoxysilane,1,3-divinyltetramethyldisiloxane, methylphenyldimethoxysilane, anddiphenyldimethoxysilane; and a cyclic siloxane such asdecamethylcyclopentasiloxane.

From the viewpoint of imparting heat resistance to the material for theparticle A and the base material particle, an ethylenically unsaturatedgroup-containing polysiloxane can be used. Examples of the commerciallyavailable product of the ethylenically unsaturated group-containingpolysiloxane include, for example, Silaplane FM-0711, Silaplane FM-0721,and Silaplane FM-0725 manufactured by JNC Corporation; X-22-174DX,X-22-2426, X-22-2475, X-22-164, X-22-164AS, X-22-164A, X-22-164B,X-22-164C, and X-22-164E manufactured by Shin-Etsu Chemical Co., Ltd.;MCS-M11, and RTT-1011 manufactured by GELEST, INC.; and AK-5, AK-30,AK-32, and HK-20 manufactured by TOAGOSEI CO., LTD.

When the particle A and the base material particle are an inorganicparticle excluding a metal particle or an organic-inorganic hybridparticle, as the inorganic substance that is a material for the particleA and the base material particle, silica, carbon black, and the like canbe mentioned. It is preferred that the inorganic substance is not ametal. As the particle formed of silica, it is not particularly limited,and for example, a particle that is obtained by hydrolyzing a siliconcompound having two or more hydrolyzable alkoxysilyl groups to form acrosslinked polymer particle, and then by firing the formed crosslinkedpolymer particle if necessary can be mentioned. As the organic-inorganichybrid particle, for example, an organic-inorganic hybrid particleformed of a crosslinked alkoxysilyl polymer and an acrylic resin, or thelike can be mentioned.

[Conductive Part]

The material for the conductive part is not particularly limited. It ispreferred that the material for the conductive part contains a metal.Examples of the metal include, for example, gold, silver, palladium,copper, platinum, zinc, iron, tin, lead, ruthenium, aluminum, cobalt,indium, nickel, chrome, titanium, antimony, bismuth, thallium,germanium, cadmium, and silicon, and an alloy thereof. Further, examplesof the metal include a tin-doped indium oxide (ITO), and solder. It ispreferred that the material for the conductive part contains nickel,gold, silver, copper, or tin because the connection resistance canfurther be reduced.

The conductive part may be formed of one layer. The conductive part maybe formed of multiple layers.

The method for forming the conductive part on a surface of the basematerial particle is not particularly limited. Examples of the methodfor forming the conductive part include, for example, a method byelectroless plating, a method by electroplating, a method by physicalvapor deposition, and a method in which a paste containing metal powderor metal powder and a binder is coated on a surface of a base materialparticle. A method by electroless plating is preferred because formationof the conductive part is simple and easy. As the method by physicalvapor deposition, a method by vacuum vapor deposition, ion plating, orion sputtering can be mentioned.

The thickness of the conductive part (thickness of the entire conductivepart) is preferably 0.5 nm or more, and more preferably 10 nm or more,and is preferably 10 μm or less, more preferably 1 μm or less,furthermore preferably 500 nm or less, and particularly preferably 300nm or less. The thickness of the conductive part is the thickness of theentire conductive layer when the conductive part is multi-layered. Whenthe thickness of the conductive part is the above lower limit or moreand the above upper limit or less, sufficient conductivity is obtained,and the particle does not become extremely hard.

[Others]

When a connection structure described iater is prepared, and the like,for the purpose of improving the adhesion with the metal atom-containingparticles described iater, a method in which fine metal particles havingeasily metal-diffusing metal atom-containing particles are disposed as asintering accelerator on a surface of a particle, or a method in whichflux is disposed as a sintering accelerator on a surface of a particlemay be employed. The particle may have fine metal particles, or may haveflux.

As the fine metal particles acting as a sintering accelerator, finemetal particles of gold, silver, tin, copper, germanium, indium,palladium, zinc, or the like can be mentioned. The fine metal particlesmay be used singly, or two or more kinds thereof in combination.Further, the fine metal particles may also be an alloy of two or morekinds of metals. In this case, a particle onto which fine metalparticles are disposed, and a sintered body constituted of metalatom-containing particles are easier to come into contact with eachother, and the adhesion is improved.

As the method for disposing fine metal particles on a surface of aparticle as a sintering accelerator, for example, a method in which finemetal particles are added into a dispersion of particles, and the finemetal particles are accumulated to be deposited on a surface of theparticle by Van der Waals force, a method in which fine metal particlesare added into a container containing particles, and the fine metalparticles are deposited on a surface of the particle by mechanicalaction such as rotation of the container, a method in which metalnanocolloids are added into a dispersion of particles, the metalnanocolloids are accumulated on a surface of the particle by a chemicalbond, the metal nanocolloids are reduced by a reducing agent, and thereduced metal nanocolloids are metallized to deposit fine metalparticles on a surface of the particle, or the like can be mentioned.From the viewpoint of easy control of the amount of fine metal particlesto be deposited, a method in which fine metal particles are accumulatedto be deposited on a surface of a particle in a dispersion is preferred.

Examples of the flux acting as a sintering accelerator includeresin-based flux, organic flux, and inorganic flux. As the resin-basedflux, rosin that has abietic acid, palustric acid, dehydroabietic acid,isopimaric acid, neoabietic acid, or pimaric acid as the main componentcan be mentioned. As the organic flux, aliphatic carboxylic acid, andaromatic carboxylic acid can be mentioned. As the inorganic flux, ahalide such as ammonium bromide, and ammonium chloride can be mentioned.The flux may be used singly, or two or more kinds thereof incombination. By the flux component disposed on a surface of a particle,an oxide film on a surface of a metal atom-containing particle isremoved, the sintering reaction is promoted on a surface of a particle,the particle and the sintered body are easier to come into contact witheach other, and the adhesion is improved.

As the method in which flux is disposed as a sintering accelerator on asurface of a particle, a method in which flux is contained into theabove-described coated part, or the like can be mentioned.

(Connecting Material)

The connecting material according to the present invention is used forforming a connection part that connects two members to be connected. Theconnecting material according to the present invention contains theabove-described particle, and a resin or metal atom-containingparticles. In this case, the connecting material contains at least oneof the resin and the metal atom-containing particles. The connectingmaterial preferably contains the metal atom-containing particles. It ispreferred that the connecting material according to the presentinvention is used for forming the connection part by melting the metalatom-containing particles followed by solidifying the metalatom-containing particles. In the metal atom-containing particles, theparticles according to the present invention are not contained.

The thermal decomposition temperature of the particles is preferablyhigher than a melting point of the metal atom-containing particles. Thethermal decomposition temperature of the particles is preferably higherthan a melting point of the metal atom-containing particles by 10° C. ormore, more preferably higher than the melting point by 30° C. or more,and most preferably higher than the melting point by 50° C. or more.

Examples of the metal atom-containing particles include metal particles,and metal compound particles. The metal compound particles contain metalatoms, and atoms other than the metal atoms. Specific examples of themetal compound particles include metal oxide particles, metal carbonateparticles, metal carhoxylate particles, and metal complex particles. Itis preferred that the metal compound particles are metal oxideparticles. For example, the metal oxide particles are sintered afterbeing formed into metal particles by heating at the time of connectionin the presence of a reducing agent. The metal oxide particles are aprecursor of metal particles. As the metal carboxylate particles, metalacetate particles, or the like can be mentioned.

As the metal constituting the metal particles and the metal oxideparticles, silver, copper, gold or the like are mentioned. Silver orcopper is preferred, and silver is particularly preferred. Accordingly,the metal particles are preferably silver particles or copper particles,and more preferably silver particles. The metal oxide particles arepreferably silver oxide particles or copper oxide particles, and morepreferably silver oxide particles When the silver particles and silveroxide particles are used, the residue is small after connection, and thevolume reduction rate is also extremely small. Examples of the silveroxide in the silver oxide particles include Ag₂O, and AgO.

It is preferred that the average particle diameter of the metalatom-containing particles is 10 nm or more and 10 μm or less. Further,from the viewpoint of increasing the connection strength of the membersto be connected, it is preferred that two or more kinds of metalatom-containing particles having different average particle diametersare contained. When two or more kinds of metal atom-containing particleshaving different average particle diameters are contained, the averageparticle diameter of the metal atom-containing particles having a smallaverage particle diameter is preferably 10 nm or more, and is preferably100 nm or less. The average particle diameter of the metalatom-containing particles having a large average particle diameter ispreferably 1 μm or more, and is preferably 10 μm or less. The ratio ofthe mixing amount of the metal atom-containing particles having a smallaverage particle diameter to the mixing amount of the metalatom-containing particles having a large average particle diameter ispreferably 1/9 or more and 9 or less. Further, the average particlediameter of the metal atom-containing particles is determined byobserving the metal atom-containing particles with a scanning electronmicroscope, and by arithmetically averaging the maximum diameters of 50particles arbitrarily selected in the observed image.

The metal atom-containing particles are preferably sintered by heatingat less than 400° C. The temperature at which the metal atom-containingparticles are sintered (sintering temperature) is more preferably 350°C. or less, and is preferably 300° C. or more. When the temperature atwhich the metal atom-containing particles are sintered is the aboveupper limit or more and less than the above upper limit, the sinteringcan be performed efficiently, further the energy necessary for thesintering is reduced, and the environmental load can be reduced.

When the metal atom-containing particles are metal oxide particles, itis preferred to use a reducing agent. Examples of the reducing agentinclude an alcohol compound (compound with an alcoholic hydroxyl group),a carboxylic acid compound (compound with a carboxyl group), and anamine compound (compound with an amino group). The reducing agent may beused singly, or two or more kinds thereof in combination.

As the above alcohol compound, alkyl alcohol can be mentioned. Specificexamples of the alcohol compound include, for example, ethanol,propanol, butyl alcohol, pentyl alcohol, hexyl alcohol, heptyl alcohol,octyl alcohol, nonyl alcohol, decyl alcohol, undecyl alcohol, dodecylalcohol, tridecyl alcohol, tetradecyl alcohol, pentadecyl alcohol,hexadecyl alcohol, heptadecyl alcohol, octadecyl alcohol, nonadecylalcohol, and icosyl alcohol. Further, as the alcohol compound, not onlya primary alcohol-type compound, but also a secondary alcohol-typecompound, a tertiary alcohol-type compound, alkanediol, or an alcoholcompound having a cyclic structure can be used. Furthermore, as thealcohol compound, a compound having a large number of alcohol groups,such as ethylene glycol, and triethylene glycol may also be used.Moreover, as the alcohol compound, a compound such as citric acid,ascorbic acid, and glucose may also be used.

As the above carboxylic acid compound, alkylcarboxylic acid, or the likecan be mentioned. Specific examples of the carboxylic acid compoundinclude butanoic acid, pentanoic acid, hexanoic acid, heptanoic acid,octanoic acid, nonanoic acid, decanoic acid, undecanoic acid, dodecanoicacid, tridecanoic acid, tetradecanoic acid, pentadecanoic acid,hexadecanoic acid, heptadecanoic acid, octadecanoic acid, nonadecanoicacid, and icosanoic acid. Further, as the carboxylic acid compound, notonly a primary carboxylic acid-type compound, but also a secondarycarboxylic acid-type compound, a tertiary carboxylic acid-type compound,dicarboxylic acid, or a carboxyl compound having a cyclic structure canbe used.

As the above amine compound, alkyl amine, or the like can be mentioned.Specific examples of the amine compound include butylamine, pentylamine,hexylamine, heptylamine, octylamine, nonylamine, decylamine,undecylamine, dodecylamine, tridecylamine, tetradecylamine,pentadecylamine, hexadecylamine, heptadecylamine, octadecylamine,nonadecylamine, and icodecylamine. Further, the amine compound may havea branch structure. Examples of the amine compound having a branchstructure include 2-ethylhexylamine, and 1,5-dimethylhexylamine. As theamine compound, not only a primary amine-type compound, but also asecondary amine-type compound, a tertiary amine-type compound, or anamine compound having a cyclic structure can be used.

The above reducing agent may also be an organic substance having analdehyde group, an ester group, a sulfonyl group, a ketone group, or thelike, or may also be an organic substance such as a metal carboxylate.The metal carboxylate is used as a precursor of metal particles, and isalso used as a reducing agent for metal oxide particles because ofcontaining an organic substance.

The content of the reducing agent based on 100 parts by weight of themetal oxide particles is preferably 1 part by weight or more, and morepreferably 10 parts by weight or more, and is preferably 1000 parts byweight or less, more preferably 500 parts by weight or less, andfurthermore preferably 100 parts by weight or less. When the content ofthe reducing agent is the above lower limit or more, the metalatom-containing particles can be sintered more densely. As a result,heat dissipation and heat resistance in a connection part can also beincreased.

When a reducing agent having a melting point lower than the sinteringtemperature (connection temperature) of the metal atom-containingparticles is used, there is a tendency that aggregation is generated atthe time of connection, and voids are easily generated in the connectionpart. By using the metal carboxylate, the metal carboxylate is notmelted by heating at the time of connection, therefore, the occurrenceof voids can be suppressed. Further, in addition to the metalcarboxylate, a metal compound containing an organic substance may beused as the reducing agent.

From the viewpoint of further suppressing the occurrence of cracking orpeeling during a thermal cycle, it is preferred that the connectingmaterial according to the present invention contains a resin. The resinis not particularly limited. The resin preferably contains athermoplastic resin, or a curable resin, and more preferably contains acurable resin. Examples of the curable resin include a photocurableresin, and a thermosetting resin. The photocurable resin preferablycontains a photocurable resin, and a photoinitiator. The thermosettingresin preferably contains a thermosetting resin, and a heat curingagent. Examples of the resin include, for example, a vinyl resin, athermoplastic resin, a curable resin, a thermoplastic block copolymer,and elastomer. The resin may be used singly, or two or more kindsthereof in combination.

Examples of the vinyl resin include, for example, a vinyl acetate resin,an acrylic resin, and a styrene resin. Examples of the thermoplasticresin include, for example, a polyolefin resin, an ethylene-vinylacetate copolymer, and a polyamide resin. Examples of the curable resininclude, for example, an epoxy resin, a urethane resin, a polyimideresin, and an unsaturated polyester resin. Further, the curable resinmay also be a room temperature curing-type resin, a heat curing-typeresin, a photo curing-type resin, or a moisture curing-type resin.Examples of the thermoplastic block copolymer include, for example, astyrene-butadiene-styrene block copolymer, a styrene-isoprene-styreneblock copolymer, a hydrogenated product of a styrene-butadiene-styreneblock copolymer, and a hydrogenated product of astyrene-isoprene-styrene block copolymer. Examples of the elastomerinclude, for example, styrene-butadiene copolymer rubber, andacrylonitrile-styrene block copolymer rubber.

From the viewpoint of further suppressing the occurrence of cracking orpeeling during a thermal cycle, it is preferred that the connectingmaterial according to the present invention contains an epoxy resin.

Since the effect of the particles of the present invention iseffectively exhibited, when the connecting material contains the metalatom-containing particles, the content of the metal atom-containingparticles in the connecting material is preferably larger than thecontent of the particles according to the present invention, morepreferably larger than the content of the particles by 10% by weight ormore, and furthermore preferably larger than the content of theparticles by 20% by weight or more.

In 100% by weight of the component excluding the dispersant of theconnecting material, the content of the particles according to thepresent invention is preferably 0.1% by weight or more, and morepreferably 1% by weight or more, and is preferably 20% by weight orless, and more preferably 10% by weight or less. When the content of theparticles is the above lower limit or more and the above upper limit orless, the occurrence of cracking or peeling during a thermal cycle canbe further suppressed. The above dispersant is removed byvolatilization.

When the connecting material contains the metal atom-containingparticles, in 100% by weight of the component excluding a dispersant ofthe connecting material, the content of the metal atom-containingparticles is preferably 70% by weight or more, and more preferably 80%by weight or more, and is preferably 98% by weight or less, and morepreferably 95% by weight or less. When the content of the metalatom-containing particles is the above lower limit or more and the aboveupper limit or less, the connection resistance is further reduced.

When the connecting material contains a resin, in 100% by weight of thecomponent excluding a dispersant of the connecting material, the contentof the resin is preferably 1% by weight or more, and more preferably 5%by weight or more, and is preferably 20% by weight or less, and morepreferably 15% by weight or less. When the content of the resin is theabove lower limit or more and the above upper limit or less, theoccurrence of cracking or peeling during a thermal cycle can be furthersuppressed.

(Connection Structure)

The connection structure according to the present invention is providedwith a first member to be connected, a second member to be connected,and a connection part that connects the first and second members to beconnected. In the connection structure according to the presentinvention, the connection part is formed of the above connectingmaterial. A material for the connection part is the above connectingmaterial.

FIG. 4 is a front sectional view schematically showing a connectionstructure using the particle according to the second embodiment of thepresent invention.

A connection structure 51 shown in FIG. 4 is provided with a firstmember to be connected 52, a second member to be connected 53, and aconnection part 54 connecting the first and second members to beconnected 52 and 53. In the connection structure 51, a particle 11 shownin FIG. 2 is used.

In the connection part 54, one particle 11 is in contact with both ofthe first and second members to be connected 52 and 53. All of theparticles 11 may not be in contact with both of the first and secondmembers to be connected 52 and 53.

In the connection part 54, particles 11, stress relaxation particles 61,and a metal connection part 62 are contained. One stress relaxationparticle 61 is not in contact with both of the first and second membersto be connected 52 and 53. The metal connection part 62 is formed bybeing solidified after melting the metal atom-containing particles. Themetal connection part 62 is a molten and solidified product of metalatom-containing particles. The stress relaxation particles 61 may not beused.

The method for producing the connection structure is not particularlylimited. As an example of the method for producing the connectionstructure, a method in which the connecting material is disposed betweenthe first member to be connected and the second member to be connectedto obtain a laminated body, and then the laminated body is heated andpressurized, or the like can be mentioned.

Specific examples of the member to be connected include an electroniccomponent such as a semiconductor chip, a capacitor, and a diode, and anelectronic component such as a circuit board of a printed board, aflexible printed board, a glass epoxy board, a glass board, or the like.The member to be connected is preferably an electronic component.

At least one of the first member to be connected and the second memberto be connected is preferably a semiconductor wafer, or a semiconductorchip. The connection structure is preferably a semiconductor device.

The first member to be connected may have a first electrode on thesurface thereof. The second member to be connected may have a secondelectrode on the surface thereof. As the electrode provided in themember to be connected, a metal electrode such as a gold electrode, anickel electrode, a tin electrode, an aluminum electrode, a copperelectrode, a silver electrode, a titanium electrode, a molybdenumelectrode, and a tungsten electrode can be mentioned. When the member tobe connected is a flexible printed board, the electrode is preferably agold electrode, a nickel electrode, a titanium electrode, a tinelectrode, or a copper electrode. When the member to be connected is aglass board, the electrode is preferably an aluminum electrode, atitanium electrode, a copper electrode, a molybdenum electrode, or atungsten electrode. Further, when the electrode is an aluminumelectrode, the electrode may be formed of only aluminum, or theelectrode may be laminated with an aluminum layer on a surface of ametal oxide layer. Examples of the material for the metal oxide layerinclude an indium oxide doped with a trivalent metallic element, and azinc oxide doped with a trivalent metallic element. Examples of thetrivalent metallic element include Sn, Al, and Ga.

Hereinafter, the present invention will be specifically described by wayof Examples, and Comparative Examples. The present invention is notlimited only to the following Examples.

(Material for Particles (Base Material Particles))

1,3-Divinyltetramethyldisiloxane (manufactured by TOKYO CHEMICALINDUSTRY CO., LTD.)

Dimethyldimethoxysilane (“KBM-22” manufactured by Shin-Etsu ChemicalCo., Ltd.)

Methylvinyldimethoxysilane (manufactured by TOKYO CHEMICAL INDUSTRY CO.,LTD.)

Methylphenyldimethoxysilane (manufactured by TOKYO CHEMICAL INDUSTRYCO., LTD.)

Methyltrimethoxysilane (“KBM-13” manufactured by Shin-Etsu Chemical Co.,Ltd.)

Isoprene (manufactured by Wako Pure Chemical Industries, Ltd.)

Divinylbenzene (“DVB960” manufactured by NIPPON STEEL & SUMIKIN CHEMICALCO., LTD.)

Polytetramethylene glycol diacrylate (“LIGHT ACRYLATE PTMGA-250”manufactured by KYOEISHA CHEMICAL Co., LTD)

1,4-Butanediol vinyl ether (“BDVE” manufactured by NIPPON CARBIDEINDUSTRIES CO., INC.)

Diisobutylene (manufactured by Wako Pure Chemical Industries, Ltd.)

Fluorene monomer (“OGSOL, EA-0300” manufactured by Osaka Gas ChemicalsCo., Ltd.)

Dicyclopentadiene (“DCPD” manufactured by TOKYO CHEMICAL INDUSTRY CO.,LTD.)

(Material other than Particles X of Connecting Material)

Silver particles (having an average particle diameter of 50 nm, and anaverage particle diameter of 5 μm)

Silver oxide particles (having an average particle diameter of 50 nm,and an average particle diameter of 5 μm)

Copper particles (having an average particle diameter of 50 nm, and anaverage particle diameter of 5 μm)

Epoxy resin (“EX-201” manufactured by NAGASE & CO., LTD.)

EXAMPLE 1

(1) Preparation of Silicone Oligomer

Into a 100-ml separable flask arranged in a warm bath, 1 part by weightof 1,3-divinyltetramethyldisiloxane (amount to be the % by weight inTable), and 20 parts by weight of a 0.5% by weight p-toluenesulfonicacid aqueous solution were placed. The resultant mixture was stirred at40° C. for 1 hour, and then into the stirred mixture, 0.05 part byweight of sodium hydrogen carbonate was added. After that, into themixture, 30 parts by weight of dimethyldimethoxysliane (amount to be the% by weight in Table), and 30 parts by weight ofmethylvinyidimethoxysilane (amount to be the % by weight in Table) wereadded, and the resultant mixture was stirred for 1 hour. After that, 1.9parts by weight of a 10% by weight potassium hydroxide aqueous solutionwas added to the mixture, the temperature was raised to 85° C., and thereaction was performed by stirring for 10 hours while reducing thepressure with an aspirator. After completion of the reaction, thepressure was returned to normal pressure, the mixture was cooled down to40° C., 0.2 part by weight of acetic acid was added to the cooledmixture, and the resultant mixture was left to stand in a separatingfunnel for 12 hours or more. The lower layer after two-layer separationwas taken out, and purified by an evaporator to obtain a siliconeoligomer.

(2) Preparation of Silicone Particles (Including Organic Polymer)

A solution A in which 0.5 part by weight oftert-butyl-2-ethylperoxyhexanoate (polymerization initiator, “PERBUTYLO” manufactured by NOF CORPORATION) was dissolved in 30 parts by weightof the obtained silicone oligomer was prepared. Further, into 150 partsby weight of ion-exchange water, 0.8 part by weight of polyoxyethylenealkyl phenyl ether (emulsifier), and 80 parts by weight of a 5% byweight aqueous solution of polyvinyl alcohol (polymerization degree:around 2000, saponification degree: 86.5 to 89% by mole, “GohsenolGH-20” manufactured by The Nippon Synthetic Chemical Industry Co., Ltd.)were mixed, and an aqueous solution B was prepared.

Into a separable flask arranged in a warm bath, the solution A wasplaced, and then the aqueous solution B was added. After that, by usinga Shirasu Porous Glass (SPG) membrane (average fine pore diameter (SPGpore diameter) of 20 μm), emulsification was performed. After that, thetemperature was raised to 85° C., and the polymerization was performedfor 9 hours. The whole amount of the particles after the polymerizationwas washed with water by centrifugation, and then the particles wereagain dispersed in 100 parts by weight of ion-exchanged water to obtaina dispersion C. Next, 0.7 part by weight of colloidal silica (“MP-2040”manufactured by Nissan Chemical Industries, Ltd.) was added to thedispersion C, and then the resultant mixture was freeze-dried to obtainbase material particles. The obtained base material particles weresubjected to classification operation to obtain particles X.

(3) Preparation of Connecting Material

By blending and mixing 49.5 parts by weight of silver particles havingan average particle diameter of 50 nm, 49.5 parts by weight (amount tobe the % by weight in Table) of silver particles having an averageparticle diameter of 5 μm, 1 part by weight (amount to be the % byweight in Table) of the above particles X, and 40 parts by weight oftoluene as a solvent, a connecting material was obtained.

(4) Preparation of Connection Structure

As the first member to be connected, a power semicondxictor element, wasprepared. As the second member to be connected, an aluminum nitrideboard was prepared.

A connecting material was applied onto the second member to be connectedso as to be a thickness of around 30 μm, and a connecting material layerwas formed. After that, the first member to be connected was laminatedon the connecting material layer, and a laminated body was obtained. Byheating the obtained laminated body at 300° C. for 10 minutes under apressure of 3 MPa, the metal atom-containing particles contained in theconnecting material were sintered, and a connection part including asintered material and particles X was formed, and then the first andsecond members to be connected were bonded by the sintered material, anda connection structure was obtained.

EXAMPLES 2 TO 9, 15 TO 21, AND 24, AND COMPARATIVE EXAMPLES 1, AND 2

Particles X, a connecting material, and a connection structure wereprepared in the similar manner as in Example 1 except that the siliconemonomer used for the preparation of the silicone oligomer was changed asshown in Tables 1 and 2, the SPG pore diameter was changed as shown inthe following Tables 1 and 2, and the constitutions of the particles andthe connecting material were changed as shown in Tables 1 and 2.

Note that in Examples 20 and 21, particles having a conductive partshown in Table 2 were prepared.

EXAMPLE 25

A Dispersion C of Example 1 was Prepared.

Based on 100 parts by weight of particles in the dispersion C, 1 part byweight of methyltrimethoxysilane (“KBM-13” manufactured by Shin-EtsuChemical Co., Ltd.), and an ammonia aqueous solution in such an amountthat the concentration of ammonia after the addition was 1% by weightwere added, and the resultant mixture was stirred at room temperaturefor 24 hours, and then the mixture was washed with water to obtain basematerial particles. The obtained base material particles were subjectedto classification operation to obtain particles X.

A connecting material, and a connection structure were prepared in thesimilar manner as in Example 1 except that the obtained particles X wereused.

EXAMPLE 10

Preparation of Isoprene Particles:

A solution A in which 90 parts by weight of isoprene as a monomer, 10parts by weight of DVB570, and 1 part by weight of benzoyl peroxide(“Nyper BW” manufactured by NOF CORPORATION) as a polymerizationinitiator were dissolved was prepared.

Further, into 800 parts by weight, of ion-exchange water, 200 parts byweight of a 5% by weight aqueous solution of polyvinyl alcohol(polymerization degree: around 2000, saponification degree: 86.5 to 89%by mole, “Gohsenol GL-03” manufactured by The Nippon Synthetic ChemicalIndustry Co., Ltd.) was mixed, and an aqueous solution B was prepared.

Into a separable flask arranged in a warm bath, the solution A wasplaced, and then the aqueous solution B was added. After that, by usinga Shirasu Forous Glass (SPG) membrane (average fine pore diameter ofaround 20 μm), emulsification was performed. After that, the temperaturewas raised to 90° C., and the polymerization was performed for 10 hours.The whole amount of the particles after the polymerization was washedwith water and acetone by centrifugation, and then the obtained basematerial particles were subjected to classification operation to obtainparticles X.

A connecting material, and a connection structure were prepared in thesimilar manner as in Example 1 except that the obtained particles X wereused.

EXAMPLES 11 TO 14

Particles X, a connecting material, and a connection structure wereprepared in the similar manner as in Example 1 except that theconstitutions of the particles and the connecting material were changedas shown in Tables 1 and 2.

EXAMPLE 22

Preparation of Fluorene Particles:

A solution A in which 100 parts by weight of fluorene monomer (“OGSOLEA-0300” manufactured by Osaka Gas Chemicals Co., Ltd.), and 1 part byweight of tert-butylperoxy-2-ethylhexanoate (“PERBUTYL O” manufacturedby NOF CORPORATION) as a polymerization initiator were dissolved wasprepared. Particles X, a connecting material, and a connection structurewere prepared in the similar manner as in Example 10 except that thesolution A in Example 10 was changed to the obtained solution A.

EXAMPLE 23

Preparation of Ring-Opening Metathesis Polymerization (ROMP) Particles:

Synthesis of a ruthenium vinylidene complex compound (compoundrepresented by the formula (2))

5.57 g (9.1 mmol) of dichloro cymene ruthenium (“Ru (p-cymene) C12”manufactured by TOKYO CHEMICAL INDUSTRY CO., LTD.), 18.2 mmol oftricyclohexylphosphine (“PCy3” manufactured by TOKYO CHEMICAL INDUSTRYCO., LTD.), 9.1 mmol of t-butyl acetylene, and 150 ml of toluene wereplaced into a 300-ml flask, and the reaction was performed at 80° C. for7 hours under a nitrogen stream. After completion of the reaction,toluene was removed under reduced pressure, and by performingrecrystallization from tetrahydrofuran/ethanol, a compound representedby the following formula (2) was obtained.

In the above formula (2), Cy represents a cyclohexyl group.

Metathesis Polymerization Reaction:

A solution in which 304 mg of the compound represented by the formula(2) (1/10000 mol equivalent of dicyclopentadiene (“DCPD” manufactured byTOKYO CHEMICAL INDUSTRY CO., LTD.) was dissolved in 30 mL of toluene wasprepared. This solution, a catalyst solution to which 25 g of allylacetate was added, and 10 mL of toluene for freezing point depressionwere added and mixed into 500 g of dicyclopentadiene (“DCPD”manufactured by TOKYO CHEMICAL INDUSTRY CO., LTD.), and the obtainedmixture was placed in a 5-L separable flask in which 1.5 kg of distilledwater was placed.

Using a mechanical stirrer, stirring was performed at 300 rpm, and thereaction was started at 30° C. Three hours after the start of thereaction, it was confirmed that a polymer was obtained, ethyl vinylether was added into the reaction mixture to terminate the reaction, andthe precipitated solid was separated by filtration and washed twice with750 mL of methanol. The obtained particles were dispersed in 500 mL ofacetone and subjected to classification operation, and then vacuumdrying was performed to obtain particles X.

A connecting material, and a connection structure were prepared in thesimilar manner as in Example 1 except that the obtained particles X wereused.

EXAMPLE 26

Particles X of Example 1 were Prepared.

Into 100 parts by weight of a solution containing 5% by weight polyvinylpyrrolidone, 10 parts by weight of particles X were added, and dispersedby an ultrasonic disperser to obtain a suspension A.

Next, 1 part by weight or metallic silver fine particles (having anaverage particle diameter of 50 nm, manufactured by Inuisho PreciousMetals Co., Ltd.) was added into the suspension A over 3 minutes, and asuspension B containing particles on the surfaces of which metallicsilver fine particles were deposited was obtained. After that, particleswere taken out by filtering the suspension B, washed with water, anddried, and as a result, particles (designated as particles X of Example26), on the surfaces of which metallic silver fine particles weredisposed, were obtained.

A connecting material, and a connection structure were prepared in thesimilar manner as in Example 1 except that the obtained particles X wereused.

EXAMPLE 27

Particles X of Example 1 were Prepared.

Into 100 parts by weight of an aqueous solution containing a 5% byweight silver nanocolloid solution, 10 parts by weight of particles Xwere added, the resultant mixture was dispersed by an ultrasonicdisperser, and then into the dispersion, 100 parts by weight of a 1% byweight solution of dimethylamine borane was slowly added, and the silvernanocolloid adsorbed onto the surfaces of the particles was reduced andprecipitated. After that, particles were taken out by filtration, washedwith water, and dried, and as a result, particles (designated asparticles X of Example 27), on the surfaces of which metallic silverfine particles were disposed, were obtained.

A connecting material, and a connection structure were prepared in thesimilar manner as in Example 1 except that the obtained particles X wereused.

(Evaluation)

(1) 10% K Value

Using “Fischer Scope H-100” manufactured by FISCHER INSTRUMENTS K.K.,the 10% K value of the particles was measured. With regard to theconductive particles, the 10% K value of the particles having aconductive part was measured.

(2) Average Particle Diameter

By observing the particles with a scanning electron microscope, and byarithmetically averaging the maximum diameters of 50 particlesarbitrarily selected in the observed image, the average particlediameter of the particles was determined. With regard to the conductiveparticles, the average particle diameter of the particles having aconductive part was measured.

(3) Thickness of Conductive Part

With regard to the particles having a conductive part, by observingcross sections of arbitrary 50 particles, the thickness of theconductive part of the particles was determined.

(4) CV Value

By observing the particles with a scanning electron microscope, thestandard deviation of the particle diameter of 50 particles arbitrarilyselected in the observed image was determined, and by theabove-described equation, the particle diameter CV value of theparticles was obtained. With regard to the conductive particles, theparticle diameter CV value of the particles having a conductive part wasmeasured.

(5) Thermal Decomposition Temperature

Using a Thermogravimeter-Differential Thermal Analyzer “TG-DTA6300”manufactured by Hitachi High-Technologies Corporation, when 10 mg ofparticles was heated at 30° C. to 800° C. (temperature rising rate of 5°C./min) under the atmosphere, the temperature at which the weight of theparticles decreased by 5% was defined as the thermal decompositiontemperature.

(6) Aggregation State

The aggregation state of particles was evaluated by using an opticalmicroscope (Nikon ECLIPSE “ME600” manufactured by Nikon Corporation).The aggregation state of particles was determined based on the followingcriteria

[Criteria for determining aggregation state of particles]

A: The number of aggregated particles per million particles is 100 orless

B: The number of aggregated particles per million particles exceeds 100

(7) Variation in Thickness

The end part of the obtained connection structure was observed with aSEM, and the minimum thickness and the maximum thickness of the bondedpart were evaluated. The variation in thickness was determined based onthe following criteria.

[Criteria for Determining Variation in Thickness]

OO: The maximum thickness is less than 1.2 times the minimum thickness

O: The maximum thickness is 1.2 times or more and less than 1.5 timesthe minimum thickness

Δ: The maximum thickness is 1.5 times or more and less than 2 times theminimum thickness

x: The maximum thickness is less than 2 times the minimum thickness

(8) Connection Strength

Using a resin paste for a semiconductor, a 4 mm×4 mm silicon chip and aback gold chip provided with a gold vapor-deposited layer on the bondedsurface thereof were mounted on a solid copper frame and a PPF (Ni—Pd/Auplated copper frame), and cured at 200° C. for 60 minutes. After thecuring and the moisture absorption treatment (at 85° C. and a relativehumidity of 85% for 72 hours), the connection strength (shear strength)at 260° C. was measured using a mount strength measuring device.

[Criteria for Determining Connection Strength]

OO: Shear strength is 200 N/cm² or more

O: shear strength is 150 n/cm² or more and less than 200 N/cm²

Δ: Shear strength is 100 N/cm² or more and less than 150 N/cm²

x: Shear strength is less than 100 N/cm²

(9) Thermal Cycle Characteristics (Connection Reliability)

The obtained connection structure was subjected to 1000 cycles of thethermal cycle test with setting a process of heating from −65° C. to150° C. and cooling to −65° C. as one cycle. The presence or absence ofthe occurrence of cracking and peeling was observed with a ScanningAcoustic Tomograph (SAT). The thermal cycle characteristics weredetermined from the occurrence of cracking or peeling based on thefollowing criteria.

[Criteria for Determining Thermal Cycle Characteristics]

OO: The number of the presence of cracking and peeling is zero out of 5samples

O: The number of the presence of cracking and peeling is 1 to 2 out of 5samples

Δ: The number of the presence of cracking and peeling is 3 out of 5samples

x: The number of the presence of cracking and peeling is 4 to 5 out of 5samples

Composition and results are shown in Tables 1 to 3.

TABLE 1 Example Example Example Example Example Example Example ExampleExample Example Example Example Example 1 2 3 4 5 6 7 8 9 10 11 12 13Particles Particles Composition 1,3-Divinyltetra- 1.6 1.6 1.6 1.6 1.61.6 1.6 1.6 1.6 X or base of methyldisiloxane material particlesDimethyl- 49.2 40.3 32.8 16.4 16.4 32.8 32.8 32.8 32.8 particles or basedimethoxysilane material Methylvinyl- 49.2 49.2 49.2 49.2 65.6 49.2 49.249.2 49.2 particles dimethoxysilane (% by Methylphenyl- 8.9 16.4 32.816.4 16.4 16.4 16.4 weight) dimethoxysilane Methyl- 16.4trimethoxysilane Isoprene 90 Divinylbenzene 10 100 70 10Polytetramethylene 30 glycol diacrylate 1,4-Butanediol 90 vinyl etherDiisobutylene Fluorene monomer Dicyclopentadiene SPG pore diameter (μm)20 20 20 20 20 5 35 80 20 20 20 20 20 Conductive Material partEvaluation 10% K value (N/mm²) 80 305 809 1490 2862 798 779 745 802 12502432 1431 526 Average particle diameter (μm) 30.5 31.1 31.5 32 30.4 11.353.2 101.1 30.8 31.2 33.5 32.8 31.1 Thickness of conductive part (nm) CVvalue (%) 2.5 2.8 2.2 2.1 2.6 2.7 2.5 2.4 8.2 2.3 2.5 2.5 2.2 Thermaldecomposition 320 335 341 347 352 356 355 355 342 262 287 248 250temperature (° C.) Aggregation state A A A A A A A A A A A A AConnecting Composition Particles X 1 1 1 1 1 1 1 1 1 1 1 1 1 materialexcluding Silver particles 99 99 99 99 99 99 99 99 99 99 99 99 99dispersant Silver oxide (% by particles weight) Copper particles Epoxyresin Connection Thickness of connection 26.8 27 27.2 27.7 27.3 8.2 4998 28 27.2 27.8 27.9 28.1 structure part (μm) Evaluation Variation in ∘∘∘∘ ∘∘ ∘∘ ∘∘ ∘∘ ∘∘ ∘∘ ∘ ∘∘ ∘∘ ∘∘ ∘∘ thickness Connection strength ∘∘ ∘∘∘∘ ∘∘ ∘ ∘∘ ∘∘ ∘∘ ∘ ∘∘ ∘ ∘∘ ∘∘ Thermal cycle ∘ ∘∘ ∘∘ ∘ ∘ ∘∘ ∘∘ ∘∘ ∘ ∘ ∘ ∘∘∘ characteristics

TABLE 2 Compar- Compar- Example Example Example Example Example ExampleExample Example Example Example ative Example ative 14 15 16 17 18 19 2021 22 23 Example 1 24 Example 2 Particles Particles Composition1,3-Divinyltetra- 1.6 1.6 1.6 1.6 1.6 1.6 1.6 1.6 1.6 1.6 X or base ofmethyldisiloxane material particles Dimethyl- 32.8 32.8 32.8 32.8 32.832.8 32.8 16.4 32.8 32.8 particles or base dimethoxysilane materialMethylvinyl- 49.2 49.2 49.2 49.2 49.2 49.2 49.2 24.6 49.2 49.2 particlesdimethoxysilane (% by Methylphenyl- 16.4 16.4 16.4 16.4 16.4 16.4 16.424.6 16.4 16.4 weight) dimethoxysilane Methyl- 32.8 trimethoxysilaneIsoprene Divinylbenzene 30 Polytetramethylene glycol diacrylate1,4-Butanediol vinyl ether Diisobutylene 70 Fluorene monomer 100Dicyclopentadiene 100 SPG pore diameter (μm) 20 20 20 20 20 20 20 20 20— 20 350 20 Conductive Material Ni Au part Evaluation 10% K value(N/mm²) 467 809 809 809 809 609 800 800 350 1050 4120 722 800 Averageparticle 31 31.5 31.5 31.5 31.5 31.5 31.6 31.6 32.2 31.8 30.1 503.2 30.2diameter (μm) Thickness of conductive 50 50 part (nm) CV value (%) 2.62.2 2.2 2.2 2.2 2.2 2.2 2.2 2.6 2.3 2.3 2.4 33.4 Thermal decomposition260 341 341 341 341 341 341 341 354 262 370 360 347 temperature (° C.)Aggregation state A A A A A A A A A A A A A Connecting CompositionParticles X 1 0.1 10 1 1 1 1 1 1 1 1 1 1 material excluding Silverparticles 99 99.9 90 99 99 99 99 99 99 dispersant Silver oxide 99 (% byparticles weight) Copper particles 99 Epoxy resin 99 ConnectionThickness of connection 28 27.2 27.2 27.2 27.2 27.2 27.5 27.6 27.6 27.829.6 496.2 29.9 structure part (μm) Evaluation Variation in ∘∘ ∘∘ ∘∘ ∘∘∘ ∘∘ ∘∘ ∘∘ ∘∘ ∘∘ ∘∘ ∘ x thickness Connection strength ∘∘ ∘∘ ∘∘ ∘∘ ∘∘ ∘∘∘∘ ∘∘ ∘∘ ∘∘ x Δ x Thermal cycle ∘∘ ∘∘ ∘∘ ∘∘ ∘ ∘ ∘∘ ∘∘ ∘∘ ∘∘ x Δ xcharacteristics

TABLE 3 Example 25 Example 26 Example 27 Particles Particles Composition1-3-Divinyltetra- 1.6 1.6 1.6 X or base of methyldisiloxane materialparticles Dimethyl- 49.2 49.2 49.2 particles or base dimethoxysilanematerial Methylvinyl- 49.2 49.2 49.2 particles dimethoxysilane (% byMethylphenyl- weight) dimethoxysilane * MethyltrimethoxysilaneComposition Isoprene excluding Divinylbenzene coated partPolytetramethylene glycol diacrylate 1,4-Butanediol vinyl etherDiisobutylene Fluorene monaner Dicyclopentadiene SPG pore diameter (μm)20 20 20 Conductive Material part Evaluation 10% K value (N/mm²) 90 8080 Average particle 32 30.5 30.5 diameter (μm) Thickness of conductivepart (nm) CV value (%) 2.5 2.5 2.5 Thermal decomposition 325 320 320temperature (° C.) Aggregation state A A A Connecting CompositionParticles X 1 1 1 material excluding Silver particles 99 99 99dispersant Silver oxide (% by particles weight) Copper particles Epoxyresin Connection Thickness of connection 27.1 26.8 26.8 structure part(μm) Evaluation Variation in ∘∘ ∘∘ ∘∘ thickness Connection strength ∘∘∘∘ ∘∘ Thermal cycle ∘ ∘∘ ∘∘ characteristics

EXPLANATION OF SYMBOLS

1: Particle

11: Particle (conductive particle)

12: Base material particle

13: Conductive part

21: Particle (conductive particle)

22: Conductive part

22A: First conductive part

22B: Second conductive part

51: Connection structure

52: First member to be connected

53: Second member to be connected

54: Connection part

61: Stress relaxation particles

62: Metal connection part

1. Particles to obtain a connecting material for forming a connectionpart that connects two members to be connected, the particles to obtaina connecting material for forming the connection part being such that athickness of the connection part after connection is twice or less anaverage particle diameter of the particles before connection, or theparticles having an average particle diameter of 1 μm or more and 300 μmor less, the particles having a 10% K value of 30 N/mm² or more and3000N/mm² or less, and the particles having a particle diameter CV valueof 10% or less.
 2. The particles according to claim 1, wherein theparticles to obtain a connecting material for forming the connectionpart being such that the thickness of the connection part afterconnection is twice or less an average particle diameter of theparticles before connection.
 3. The particles according to claim 1,wherein the particles have an average particle diameter of 1 μm or moreand 300 μm or less.
 4. The particles according to claim 1, wherein thenumber of aggregated particles per million particles of the particles is100 or less.
 5. The particles according to claim 1, wherein theparticles have a thermal decomposition temperature of 200° C. or more.6. The particles according to claim 1, wherein a material for theparticles contains a vinyl compound, a (meth)acrylic compound, anα-olefin compound, a diene compound, or a silicone compound.
 7. Theparticles according to claim 1, wherein the particles each have noconductive part on an outer surface part thereof.
 8. The particlesaccording to claim 1, wherein the particles each have a base materialparticle, and a conductive part disposed on a surface of the basematerial particle.
 9. The particles according to claim 8, wherein amaterial for the conductive part contains nickel, gold, silver, copper,or tin.
 10. The particles according to claim 1, wherein the particles toobtain a connecting material for forming the connection part being suchthat one particle is in contact with both of the two members to beconnected.
 11. A connecting material for forming a connection part thatconnects two members to be connected, comprising: the particlesaccording to claim 1; and a resin or metal atom-containing particles.12. The connecting material according to claim 11, wherein theconnecting material contains the metal atom-containing particles, and athermal decomposition temperature of the particles is higher than amelting point of the metal atom-containing particles.
 13. The connectingmaterial according to claim 11, wherein the connecting material containsthe metal atom-containing particles, and the connecting material forforming the connection part are prepared by melting the metalatom-containing particles followed by solidifying the metalatom-containing particles.
 14. A connection structure, comprising: afirst member to be connected; a second member to be connected; and aconnection part that connects the first member to be connected and thesecond member to be connected, a material for the connection part beingthe connecting material according to claim 11.